The invention relates to cassettes for photographic elements and, more particularly, to a cassette for an x-ray phosphor film plate of the kind used in computed radiography.
In computed radiography, a photographic element has an image formed thereon by x-rays, and the element is subsequently provided to a reader where the photographic element is stimulated to emit a radiation pattern that is captured for storage and use. Cassettes of the kind used in computed radiography may comprise a container having upper and lower parts that are hinged together so that they can be opened for insertion of a thin, flexible film sheet or rigid film plate comprising the photographic element. The cassette is closed and latched so that the cassette with the element therein can be used with an x-ray apparatus to produce an image on the photographic element. Then the cassette is taken to a reader where the cassette must be opened and the photographic element extracted by suitable feeders, such as suction feeding devices. The photographic element separate from the cassette is transported through the reader where it is stimulated to emit a radiation pattern and subsequently erased before being returned to the cassette for re-use. The cassettes and photographic elements as described above have generally been satisfactory, however, the cassettes can be relatively expensive, and flexible photographic elements require special feeding devices for extracting them from the cassette and returning them to the cassette. A cassette disclosed in U.S. patent application Ser. No. 728,432 filed Jul. 11, 1991 by Jeffrey C. Robertson, minimizes cost of the cassette and simplifies delivery of the photographic element to the reader for image processing. An extractor having a series of hooks can enter that cassette and engage and extract a removable photographic element assembly. That cassette has the shortcomings, that the photographic element assembly is difficult to remove from the cassette manually for cleaning and the like, that the cassette does not include an x-ray grid and that the x-ray film element forms the bottom of the cassette.